The present invention concerns methods of improving shrink-resistance of natural fibers (e.g., wool, wool fibers, animal hair, cotton), synthetic fibers (e.g., acetate, nylon, polyester, viscose rayon), or blends thereof (e.g., wool/cotton blends), or fabrics or yarns composed of natural fibers, synthetic fibers, or blends thereof, involving contacting the fibers (or fabric or yarn) with NaOH, H2O2, gluconic acid, dicyandiamide, and non-ionic surfactant (e.g., Triton X surfactant such as Triton X-100 and preferably Triton X-114), and optionally subsequently contacting the fibers (or fabric or yarn) with protease and non-ionic surfactant and optionally sodium sulfite and optionally triethanolamine and optionally polyacrylamide polymer. The methods do not utilize dichloroisocyanuric acid, chloroamines, peroxymonosulfuric acid, monoperoxyphthalic acid, permanganate, chlorine gas, sodium hypochlorite, or aminoplast resins.
The demand for shrinkage resistance in wool products has led to the development of effective chlorinated systems. However, the perceived drawback to their use is the production of adsorbable organic halogens (AOX). Thus alternative systems relying upon other compounds are now under investigation.
We now report on H2O2 processes, some with protease enzyme, and the selectivity of these processes to remove wool's hydrophobic layer and form anionic surface charge while causing scale smoothing to achieve shrinkage control. We also investigated alkaline peroxide/gluconic acid/dicyandiamide pretreatment followed by application of protease in buffered triethanolamine solution to which sodium sulfite was added.